Cryo and detergents 晶体的冷冻和清洁剂
(Be aware of the potential for) detergent concentration mismatch between your mother liquor and the cryosolution. This particularly happens with vapor diffusion setups: there is a delicate balance of “free” detergent in the mother liquor versus the proportion of the detergent which is bound to the protein. Dropping a xtal into the cryosolution shocks the crystal with a bolus of extra free detergent. Hence, and counterintuitively, you may need to reduce the detergent concentration in the cryosolution to keep everything in balance. Try titrating down from 1% to even as low as 0.4% in the cryosolution. Under the conditions you are using the CMC of bOG is suppressed below the usual 0.67% (w/v).
Also, the behavior of many of the alkyl glycoside detergents is very temperature sensitive. So be careful about the temperature of all the solutions you use.
R. Michael Garavito, Ph.D.
Submitted to CCP4 bulletin board February 2007
Edited by Hampton Research Corp.
(请注意)母液和冷冻溶液之间的洗涤剂浓度不匹配的可能性。 这尤其发生在蒸汽扩散装置中:母液中的“游离”去污剂与与蛋白质结合的去污剂比例之间存在微妙的平衡。 将 xtal 滴入冷冻溶液中会用一团额外的游离洗涤剂冲击晶体。 因此,与直觉相反,您可能需要降低冷冻溶液中的洗涤剂浓度以保持一切平衡。 尝试在冷冻溶液中从 1% 滴定到甚至低至 0.4%。 在您使用的条件下,bOG 的 CMC 被抑制在通常的 0.67% (w/v) 以下。
此外,许多烷基糖苷去污剂的行为对温度非常敏感。 因此,请注意您使用的所有溶液的温度。